Remove /crowd segment from the URL.

The '/crowd' URL prefix shall be set in the 'auth_crowd_url' in the nginx settings in order to allow to use installations exposed on '/' instead of '/crowd'
Update README to add the /crowd suffix.
Passing the correct 'remote_address' value to crowd.
Merge pull request #2 from GaretJax/master

Remove hardcoded '/crowd' prefix from URLs